1. Field of the Invention
The invention concerns an X-ray powder diffractometer having a source for producing a monochromatic X-ray beam and a detector with position-sensitive behavior for carrying out intensity diagram plots of the positional disperson of the X-ray beam in Bragg-Brentano, Guinier, or Seeman-Bohlin analyses of fine crystalline materials.
2. Description of the Prior Art
X-ray particle diffractometers of the kind described herein are known and are used for diffractometer processes according to Bragg-Brentano, Guinier, Seemann-Bohlin and others like them. Such an X-ray powder diffractometer is described, for example, in Fundamentals and Application of X-ray Fine Structure Analysis, Hans Neff, Oldenburg Publishing House, 1959, particularly at page 200.
With such diffractometers, radiographic analyses are carried out on fine crystalline materials. In principle FIG. 1 illustrates a known arrangement for the Bragg-Brentano process of diffraction analysis. The X-ray beam, which emanates from a source 1 for monochromatic X-ray transmission, passes through an aperture stop 2 and strikes sample 3. This sample 3 provides a pattern which is analyzed through an angle .theta.. The beam 4, which has been deflected by the sample, has focusing areas which lie on an arc 5 according to the angle of deflection. It is common practice to record the intensity which occurs in the region of the aperture stop 7 and which is dependent on angle .theta. in order to produce and intensity distribution. A detector 6 is employed which is sensitive to position and which is illustrated with a line and provided with aperture stop 7 adjacent thereto. It is also common practice to arrange the receiving surface of detector 6 as indicated by the line in the figure. This orientation of the receiving surface of detector 6 deviates from arc 5 for the position of sharp focusing, this deviation being reasonable, however, when a sufficiently close aperture stop 7 is employed. This deviation has as its purpose the arrangement of detector 6 in a simpler manner in the mechanism. In addition it is necessary in order to properly establish the position sensitive behavior of detector 6 that the deflected X-ray beam 4 be received as perpendicular as possible relative to the receiving surface of detector 6.
From the prior art it is known to record the so-called powder diagram point-by-point through the given angle .theta. with the detector 6 on the measured arc 8. This recording requires considerable expenditure of time in order to cover the entire angle .theta. along arc 8 point-by-point, as is normal practice, where a sector angle of approximately 160.degree. is to be covered.
In order to cover this sector of the measured arc 8, the detector 6 is shifted step-wise by given angle increments in which case it is essential that the angle at which detector 6 is set each time is as precise as possible so that different powder recordings can be combined with each other. A precise setting of the prescribed angular position requires a correspondingly precise mechanical construction and a suitable guidance system. Particular difficulties occur if the step-wise thrust occurs especially quickly to permit the total recording of the powder diagram to be carried out as quickly as possible over the total measured arc 8 as described above. Particular difficulties also occur for the intensities at the boundaries between subsequent parts of the arc.